Patent GB-376128-A (GB)
Title: Electric time or impact fuses for projectiles and the like
IPC: F42C11/06
Filed: 1931-10-24
Abstract: 376,128. Electric fuzes for projectiles and mines. RHEINISCHE METALLWAAREN - UND MASCHINENFABRIK, 195, Ulmenstrasse, Derendorf, Dusseldorf, Germany. Oct. 24, 1931, No. 29561. Convention date, April 11. [Class 9 (i).] Relates to fuzes in which electric igniters are fired by means of condensers, and consists mainly in the provision of two condensers, one a fuze condenser for firing the fuze, and the other a storage condenser from which the charge of the fuze condenser is supplied or completed a given time after the storage condenser has itself been charged by an internal or external source. As shown in Fig. 1, a storage condenser a in a projectile c is charged from an external source i<1>, i<2> through an insulated contact e and a switch d<1>, which closes by inertia when the projectile is discharged and opens again when acceleration is over. A fuze condenser b is then charged :from the storage condenser a through a resistance f which prevents the voltage of the fuze condenser from rising to the operative value until after a certain time during which the fuze remains safe. After this, an electric igniter g is fired by the fuze condenser b when an inertia switch h is closed by impact. In a modification, the inertia switch is replaced by a switch in the nose of the projectile comprising a disc adapted to be deflected by the target to make contact with an insulated terminal behind it. In another modification, Fig. 5, a plunger switch k, k<1>, k<2> is provided and operated by a supply contact i<1>, so that when the storage condenser a is being charged, it. is cut off from the resistance f leading to the fuze condenser b, and the igniter g is short-circuited. The plunger switch may be made to cut off the resistance f only or to short the igniter g only, instead of doing both as above. In the above constructions, the body of the projectile is used as one of the connections. In certain modifications, all the parts of the circuits are insulated from the body of the projectile. In other modifications, the set of condensers is duplicated, or the fuze condenser only is duplicated, so that one may be used for one function and the other for another function. For example, one may explode the projectile with delay and the other without, in which arrangement spark-gap devices may be used in the circuits. In another arrangement, Fig. 10, a fuze U<1> acts on impact as described above, but is disarmed on striking water by a short circuit at m before the inertia switch h of this fuze can operate ; at the same time another short circuit at n connects the fuze condenser b of a second fuze on the right of the first one U<1> to its storage condenser a to receive a charge in readiness to fire the fuze on impact with a solid body under the water. In still another modification, Fig. 13, the fuze is arranged to act as a time fuze to explode the projectile a given time after its discharge. In this case the inertia switch in the circuit of the electric igniter g is replaced by a sparkgap device l which passes the igniting current when the voltage of the fuze condenser b reaches a predetermined value after a certain time determined by the capacities of the condensers b, a, the value of the resistance f and the initial voltage applied to the condenser a, which in this case is fed through a switch d<2> connecting the condenser a to the supply i<1> at the moment cf discharge and after this to the resistance f. If desired a partial charge may be given to the fuze condenser b by a separate contact e<1>.